Osteology of Skull and Cervical Spine Flashcards Preview

ESA 4 - Head and Neck > Osteology of Skull and Cervical Spine > Flashcards

Flashcards in Osteology of Skull and Cervical Spine Deck (170):
1

What are the categories of cervical vertebrae? 

  • Typical
  • Atypical

 

2

What does wether a cervical vertebrae is typical or atypical depend on? 

Their osteological features

3

What are the atypical cervical vertebrae? 

C1, C2, and C7 

4

What is C1 known as? 

Atlas

5

What shape is C1? 

Ring shaped 

6

What is the function of the atlas? 

Supports the skull at the atlanto-occipital joint 

7

What does the atlas articulate with inferiorly? 

The second cervical vertebrae

8

What is C2 known as? 

Axis

9

How does the strength of the axis compare to other cervical vertebrae? 

It is the strongest of all cervical vertebrae

10

Why is the axis need to be the strongest cervical vertebrae? 

Because C1, carrying the skull, rotates on it 

11

What feature does C2 have? 

Odontoid process (the dens) 

12

Where does the odotoid process project? 

Superiorly from its body 

13

How is the odontoid process held in position? 

By strong transverse ligament of atlas 

14

What is the function of the transverse ligament of the atlas? 

Prevents horizontal displacement of the atlas, thus stabilises the atlanto-axial joint 

15

What is the bony skeleton of the neck formed by? 

The 7 cervical vertebrae

16

Where do the cervical vertebae lie? 

Between the skull and the thorax

17

What is found between each vertebrae? 

An intervertebral disc 

18

What is the exception to there being an intervertebral disc between vertebrae? 

There is no vertebral disc between C1/2

19

Why is there no intervertebral disc between C1/2? 

Because C1 has no vertebral body 

20

How do the cervical vertebrae differ in function to other vertebrae in the body functionally? 

  • They bear less weight than vertebrae in other regions of the body 
  • Convey a much greater degree of mobility 

 

21

How do cervical vertebrae differ from other vertebrae in the body structurally? 

  • Much smaller
  • Have a foramen in each of their transverse processes 
  • Vertebral foramen is much larger
  • Articular surfaces are more horizontally orientated 

 

 

22

Why do cervical vertebrae have a foramen in each of their transverse processes? 

Transmit vertebral arteries on their way to supply the back of the brain 

23

Which cervical vertebrae doesn't have transverse foramen? 

C7

24

Why is the vertebral foramen of cervical vertebrae much larger than other vertebrae in the body? 

Accommodate much thicker cervical spinal cord 

25

What happens to the vertebral foramen the more caudal it goes? 

It gets smaller 

26

Why does the vertebral foramen get smaller as it runs more caudally? 

Because the spinal cord it transmits gets thinner, as more and more nerves leave the spinal cord  to innervate various structures 

27

What is the result of the articular surfaces of cervical vertebrae being more horizontally orientated than in other vertebrae? 

They can dislocate or 'slip off' at much less force than is required for them to fracture 

28

What is the skull? 

The collective term referring to the complete skeleton of the head 

29

What does the skull include? 

  • Cranium 
  • Mandible

 

30

What can the cranium be further subdivided into? 

  • Neurocranium 
  • Viscerocranium 

 

31

What is the neurocranium? 

The bones forming a protective box around the brain 

32

What is the viscerocranium? 

Bones forming facial skeleton 

33

What does the neurocranium consist of? 

  • Calvaria
  • Cranial floor 

 

34

What is the calvaria? 

The skull, or cranial, cap 

35

What is the lower limit of the calvaria? 

It has no lower limit to it as such 

 

36

What do the bones of the calvaria consist of? 

Two layers of bones, seperated by a layer of spongy bone 

37

What is the layer of spongy bone in the calvaria known as? 

Diploe 

38

What is true of the innermost layer of the calvaria in adults? 

It is particularly brittle 

39

What is the purpose of the trilaminar arrangement of bone in the calvaria? 

It conveys protective stength, without adding significant weight 

40

What is the thinnest part of the calvaria? 

The pterion

41

Where does the pterion lie? 

On the lateral aspect of the skull 

42

What is between the large, flat bones forming the calvaria? 

Sutures 

43

What are sutures? 

Serrated, immobile joints of strong fibrous tissue 

44

What are the names of the sutures? 

  • Coronal 
  • Sagittal
  • Lamboid 

 

45

What is the clinical relevance of sutures? 

  • Interlocking nature of these joints makes it very different or bones forming the joint to dislocate
  • As we age, suture lines begin to ossify 

 

46

What is the cranial floor divided into? 

Three areas, or fossa

47

What are the areas of the cranial floor? 

  • Anterior
  • Middle
  • Posterior

 

48

What is found in the cranial floor? 

A number of foramina (holes)

 

49

What is the function of the holes in the cranial floor? 

Allow for passage of anatomical structures between extra- and intra-cranial compartments 

50

What structures pass through the foramen in the cranial floor? 

  • Cranial nerves
  • Blood vessels

 

51

What is the clinical relevance of the large number of foramina in the cranial floor? 

Make the cranial floor vulnerable to fracture 

52

When can the vertebral floor fracture? 

When significant force is transmitted through the skull base

53

What is the viscerocranium formed by? 

  • Bones enclosing the orbits
  • Nasal cavity
  • Oral cavity
  • Paranasal sinuses
  • Maxillae 
  • Mandible 

 

54

What is the maxillae? 

The upper jaw

55

What is the mandible? 

The lower jaw

56

What does the jaw house? 

The teeth

57

What are the main features of the anterior aspect of the skull? 

  • Frontal bones
  • Zygomatic bones
  • Orbits
  • Nasal region
  • Maxillae
  • Mandible

 

58

What do the frontal bones form? 

Skeleton of forehead

59

What does the frontal bone articulate with? 

  • Nasal bones 
  • Zygomatic bones
  • Lacrimal bones
  • Ethmoid bones
  • Sphenoid bones 

 

60

What do the frontal bones form? 

  • Roof of orbit
  • Part of floor of cranial cavity 

 

61

What are the zygomatic bones? 

Cheek bones 

62

Where do the zygomatic bones lie? 

On the inferolateral sides of orbits 

63

What do the zygomatic bones articulate with? 

  • Frontal bone 
  • Sphenoidal bone
  • Temporal bone
  • Maxillae 

 

64

What does the maxillae constitute? 

The greater part of the upper facial skeleton

65

What is the maxillae fixed to? 

Cranial base 

66

Why is the mandible moveable? 

Because it articulates with the cranial base at the temporomandibular joint 

67

Why is the temporomandibular joint special? 

It is the only moveable joint of the skull 

68

What is found just above the orbital margin? 

Supraciliary arch

69

What is the supraciliary arch? 

A sharp bony ridge

70

Will slight dislocation of the cervical vertebrae damage the spinal cord? 

It may or may not 

71

Why may slight dislocation of the cervical vertebrae not damage the spinal cord? 

Due to large vertebral canal in cervical region 

72

What may significant dislocation of the cervical vertebrae cause? 

Serious injuries to the spinal cord 

73

What serious injuries to the spinal cord can be caused by significant dislocation of the cervical vertebrae? 

  • Partial paralysis 
  • Complete paralysis 
  • Death 

 

74

What are the most common sites of cervical spine injuries? 

  • C1/2
  • C6
  • C7 

 

75

Where do most severe (often fatal) spinal injuries occur? 

In the upper part of the spine (C1-4)

76

What does damage to the upper part of the spine lead to? 

  • Quadriplegia
  • Cessation of respiratory movements 

 

77

When may a hyperflexion of the cervical spine injury occur? 

 

During head on collision 

78

What do hyperflexion injuries of cervical spine tend to involve? 

Lower part of cervical spine

79

What can hyperflexion injuries of the cervical spine lead to? 

  • Crush factors of the vertebral body 
  • Rupture of supraspinous ligament 
  • Rupture of lower cervical intervertebral discs

 

80

Give an example of a crush fracture of the cervical spine? 

Cervical wedge fracture

81

Is a cervical wedge fracture stable? 

May be, if just one vertebra is involved 

82

How will a cervical wedge fracture present on x-ray? 

Loss of height of vertebral body 

83

What are crush fractures of the vertebral body associated with? 

Spinal degenerative disease

84

Give an example of a spinal degenerative disease? 

Osteoporosis 

85

What is the effect of the rupture of the supraspinous ligament? 

Makes bony spine unstable

86

What cervical intervertebral discs can rupture? 

  • C5/6
  • C6/7 

 

87

What complication can rupture of the lower cervical spinal discs cause? 

May cause compression of spinal nerve roots C6 and C7 

88

What are hyperextension injuries of the neck associated with? 

Rear-end vehile collision 

89

What do hyperextension injuries of the neck most commonly affect? 

Upper cervical spine 

90

What can hyperextension injuries of the neck result in? 

  • Vertebral fracture
  • Disc prolapse
  • Cervical spinous process or odontoid process fracture
  • Tearing of anterior longitudinal ligament 
  • Kinking of posterior longitudinal ligament 

 

91

Where may hyperextension injuries of the neck cause kinking of the posterior longitudinal ligament? 

In the degenerative spine 

92

What is the protective function of car seat head rests? 

They act to minimise the range of hyperextension that can occur at the neck

93

What is a Hangmans Fracture? 

A type of injury that can occur caused by hyperextension of the neck

94

When may a Hangmans Fracture occur? 

During judicial hanging, not suicidal hanging

 

95

What is the cause of death in suicidal hanging? 

Asphyxiation 

96

What happens in a Hangmans Fracture? 

Bilateral fracture of posterior arch of C2, and disruption of C2-3 junction 

97

Is a hangmans fracture stable? 

No

98

What is the result of a Hangmans Fracture being unstable? 

There is a risk of C2 displacement and spinal cord damage

 

99

What needs to be done when someone presents with a Hangmans Fracture? 

MRA

100

Give an example of how an axial load injury through the head and neck may occur? 

Falling onto head from height

101

What may an axial load injury through the head and neck cause? 

Jeffersons fracture 

102

What is a Jeffersons fracture? 

A burst fracture of C1 

103

What happens in a Jeffersons fracture? 

Combination of anterior and posterior arch fractures 

104

Is a Jeffersons fracture unstable? 

It can be 

105

What may be neccessary if a Jeffersons fracture is unstable? 

External fixation

106

Why must patients presenting with a suspected neck injury be managed carefully? 

Avoid (further) damage to the cervical spinal cord 

107

Do all neck injuries or cervical fractures cause damage to the spinal cord? 

No 

108

What should happen to any patient with significant mechanism for neck injury? 

They should have full in-line spinal immobilisation

109

Why should all patients with significant mechanism for spinal injury have full in-line spinal immobilisation? 

Due to the potentially catastrophic neurological consequences should spinal injury occur 

110

What does full in-line spinal immobilisation include? 

Immobilisation of the cervical spine with; 

  • Appropriately sized semi-rigid collar
  • Head blocks
  • Tape

And rest of patients spine immoblised on a spinal board

 

111

When is immobilisation no longer required following a spinal injury? 

When the cervical spine has been 'cleared'

112

When can the cervical spine be 'cleared' after injury? 

When the patient is determined to be at minimal risk for spinal injury

113

What does the clearing of a C-spine follow? 

Thorough clinical examination 

114

What is the clearing of a C-spine based on? 

Specific criteria, e.g. Canadian C-spine rules 

115

What should be done if any doubt remains about possibility of spinal injury, or risk to spine, and the C-spine cannot be cleared confidently by clinical examination? 

Radiological examinations undertaken 

116

What radiological examinations can be undetaken to clear a C-spine? 

  • Plain radiography, involving 3 views of the cervical spine 
  • CT 

117

When is an x-ray used as the radiological examination to clear C-spine? 

In paediatrics 

118

Why are x-rays used to clear the C-spine in paediatrics? 

Because don't want radiation around structures of the neck, e.g. the thymus 

119

What would happen if a fracture or other injury was identified on radiological imaging of the C-spine? 

Further management would depend on the type of injury found 

120

What are the facet joints of the vertebral arches (zygopophyseal joints) close to? 

Intervertebral foramina 

121

What emerges through the intervertebral foramina? 

Spinal nerves 

122

What happens if the zygapophyseal joints are affected by osteoarthritis? 

Intervertebral foramen can narrow 

123

What can age related changes in intervertebral discs cause? 

Cause the discs to bulge, narrowing the intervertebral foramen 

124

What can narrowing of the intervertebral foramen cause? 

Compression of the spinal nerve exiting at that vertebral level

125

Give two pathologies resulting from narrowing of the intervertebral foramen? 

  • Cervical spondylotic myelopathy
  • Cervical spondylotic radiculopathy 

 

126

What happens in cervical spondylotic myelopathy? 

Spinal cord compression 

127

What does cervical spondylotic myelopathy lead to? 

  • Loss of function
  • Often loss of fine motor skills in upper limbs 

 

128

What happens in cervical spondylotic radiuclopathy? 

Nerve root impingement 

129

What does cervical spondylotic radiculopathy lead to? 

Dermatomal arm pain, with or without mild weakness and sensory loss 

130

What can osteoarthritis of the C-spine lead to? 

Cervical spondylosis 

131

In laymans terms, what is cervical spondylosis? 

'Wear-and-tear' of C-spine vertebrae

132

Who does cervical spondylosis affect? 

Older population 

133

How common is cervical spondylosis? 

Very common 

134

What are the features of cervical spondylosis? 

  • Osteophytes
  • Facet joint hypertrophy
  • Disc herniation
  • Disc space narrowing
  • Sclerosis of end plates 

 

 

 

135

What are osteopytes?

Bony spurs

136

What may severe blows to the skull result in? 

  • Local depression and splintering of bone
  • Series of linear fractures radiating away from the initial point of injury

 

137

What severe trauma to the skull may result in fractures? 

Impact injuries or blows

138

What complications can arise from skull fractures? 

Can damage underlying brain and/or blood vessels 

139

What does bleeding into the cranial cavity cause? 

Haematoma 

140

What are the types of intracranial haematoma? 

  • Epidural 
  • Extradural 
  • Subdural 

 

141

Where does an extradural haematoma occur? 

Between skull periosteum and outermost meningeal layer 

142

What is the outermost meningeal layer? 

Dura mater 

143

What happens in an extradural haematoma? 

It bleeds into the skull at high pressure, which can press on the brain, causing abnormal neurology 

144

Wha is an extradural haematoma associated with? 

Trauma and skull fracture 

145

What is it important to do when a patient presents with a head injury? 

  • Examine head and any wounds thoroughly
  • Undertake neurological assessment

 

146

What should be determined in a neurological assessment? 

If there is evidence, or risk of, brain injury 

147

What should be done when there is clinical suspicion of intracranial haemorrhage? 

  • CT imaging of head
  • Consideration to possibility of C-spine injury

 

148

What is a basilar skull fracture? 

Fracture through cranial floor

149

When can a basilar skull fracture occur? 

If significant force is transmitted through the vertebral column 

150

Why can a basilar skull fracture occur if significant force is transmitted through vertebral column? 

Because base of skull is connected to vertebral column 

151

How does a basilar skull fracture present? 

  • Battle's sign
  • 'Raccoon' eyes
  • Haemotympanum
  • Meningeal tears
  • Cranial nerve palsies

 

152

What is Battle's sign? 

Bruising over mastoid process

153

What is 'Raccoon' eyes? 

Bruising around both eyes 

154

What is haemotympanum? 

Blood behind ear drum 

155

What results from meningeal tears? 

Bleeding and/or CSF leakage from; 

  • Ear
  • Nose

 

156

What is is called when CSF leaks from the ears? 

CSF otorrhea

157

What is it called when CSF leaks from the nose? 

CSF rhinorrhea

158

Why may a basilar skull fracture lead to cranial nerve palsies? 

As cranial nerves run along base of skull in many cases 

159

What is there a risk of in basilar skull fractures? 

  • Meningtis
  • Need for neurosurgical intervention 

 

160

How common are basilar skull fractures? 

Uncommon, less than 5% of skull fractures

161

What does a fracture at the pterion risk? 

Injuring the middle meningeal artery (anterior branch) 

162

Why does a fracture at the pterion risk damaging the middle mengingeal artery? 

As it lies immediately beneath the bone 

163

What will bleeding from the anterior branch of the middle meningeal artery cause? 

Extradural haematoma 

164

What happens in an extradural haematoma from the anterior branch of the middle meningeal artery? 

Blood accumulates between the periosteal layer of dura mater and the bone, exerting pressure on underlying brain

165

How are injuries to the facial skeleton caused? 

  • Road traffic collisions
  • Fights
  • Falls

 

166

What do the most common facial fractures involve? 

  • Nose
  • Zygomatic bone
  • Mandible 

 

167

Why are fractures of the nasal bone common? 

Because of the prominence of the nose 

168

What does a hard blow to the lower jaw often result in? 

Fracture of the neck of the mandible and its body 

169

What may fracture of the mandible be associated with? 

Dislocation of the temporomandibular joint 

170

What is required to fracture the maxillary and frontal bones? 

Significant force